Adapter for stator assemblies



May 19, 1964 134,034

F. w. KUHAGEN 3, ADAPTER FOR STATOR ASSEMBLIES TO CONCENTRATE THE FLUX PATHS THEREFROM Filed Aug. 9, 1960 INVENTOR: FRED W. KUHAGE Y United States Patent Illinois Filed Aug. 9, 1960, Ser. N0.'48,402

3 Claims. (Cl. 310-19) This invention relates generally to electromagnetically operated devices andmore particularly to an improvement for a stator structure utilized within the electromag netically operated devices.

The invention finds particular application in hand tools such as clippers, razors, massagers, etc., in which a reciprocating motion set up by an armature, is utilized. These electromagnetically operated hand devices, as well as. larger vibrating units, usually utilize an E-shaped laminated stator powered by an electrical A.C. coil placed upon its center post to operate or vibrate a reciprocating armature. As the armature is operated, an increase in temperature is evidenced in the AC. coil up to a maximum temperature level. As the temperaturerises in the AC. coil, there will be an appreciable change of magnetic power and a resetting of the armature will be required if a constant torque measurement is to be maintained. It is readily apparent that the rise in temperature in the AC. coil will cause an increased wattage consumption, if there is to be a constant magnetic power output.

The temperature increase of the electromagnetically operated hand devices of today not only require an increase of power, but the elevated temperatures transmitted to adjacent operating parts has a tendency to decrease the life expectancy and the continuous smooth operation of these parts. It is also apparent, to one that has used "these devices, that any increase of temperature becomes very uncomfortable to the operator, especially in a shaving device.

It is therefore, the primary object of this invention to provide a new and improved stator construction for use in electromagnetic devices, wherebythe above problems of the prior art are substantially reduced.

A specific object of this invention is to provide a new and improved adapter for a stator assembly to effectively decrease the'temperature rises created in a stator coil when in continuous operation.

Another object of this invention is to provide a new and improved adapter that is capable of being mounted on existing stator assemblies to effectively reduce the temperature rise in the stator coil.

'A still further object of this invention is to provide a new and improved stator adapter wherein a maximum magnetic force output is attained from a minimum of power input.

Another object of this invention is to provide a new and improved stator adapter that is simple in design, inexpensive to manufacture, and readily adaptable to existing stator assemblies.

With these objects and other features and advantages of this invention in mind, which will appear from the following specification and claims, taken in connection with the drawings, the invention consists in the novel construction, arrangement, and formation of the parts.

In brief, the applicants invention comprises an adapter which is preferably circular in shape like a thin washer and has depending leg members extending at right angles from one of its surfaces. The adapter, made from a magnetic material, is placed on the center post of an E-shaped stator assembly with the depending leg members forced between the center post and the inner walls of an AC. coil. To further secure the adapter to the E-shaped stator assembly, two of the corners of the end surface of the center post are upset whereby the stator material engages the adapter to force it outwardly into a binding relationship with the AC. coil.

So that the present invention may be more clearly presented and more easily understood, the applicant now refers to the drawings in which:

FIG. 1 is a perspective view in side elevation of a stator assembly having the adapter of this invention mounted thereon;

FIG. 2 is a top view of the stator structure having the adapter of this invention applied thereto;

FIG. 3 is a section view in side elevation of the structure of this invention taken along the line 3-3 of FIG. 1 with a fragmentary showing of an armature;

FIG. 4 is a perspective view of the adapter of this invention;

FIG. 5 is a section view in side elevation of the adapter of this invention taken along line 5-5 of FIG. 4;

FIG. 6 is a perspective view of another embodiment of the adapter of this invention;

FIG. 7 is a top view of another embodiment of the adapter of this invention; and

FIG. 8 is a view in side elevation of the embodiment of this invention shown in FIG. 7.

Referring now to the drawings, the stator assembly to which this invention is applied is indicated generally by the numeral 10 and comprises an E-shaped laminated stator 12 and an A.C. coil 14 which is mounted on a center post 16 of the stator.

An armature assembly 18, while being an integral portion of the motor to which this invention is applied, will not be described in detail and has been only partially illustrated, as the structure provided by this invention is applied only to the stator assembly 10.

The stator 12 consists of a plurality of laminated E-shaped magnetic core members 20 which are rigidly secured, by any of the well-known staking methods of today, to prevent pressure variables due to temperature changes which would alter the reluctance characteristics from a desired constant value.

' The AC. coil 14 is preferably any suitable commercially produced coil which is provided with insulated end surfaces 22 and an insulated central opening 24. As readily viewed in FIG. 3, the continuous insulation at the ends and through the center of the coil completely insulates the coil from the stator center post 16. The dimensions of the central opening 24 being substantially greater thanthe external dimensions of the center core post 16 allows the coil 14 to be pressed onto'the center post.

Referring now to FIGS. 4 and 5, the preferred embodiment of the adapter of this invention is indicated by the numeral 26 as being circular or washer-shaped and is formed from a suitable magentic material such as steel. An upper circular washer portion 28 is preferably formed to an overall thickness of a few thousandths of an inch, the thickness varying with the different size coils. A central opening 30, having an internal contour substantially the same as the center post 16, is centrally located in the washer portion 28 and provides individual side walls or tabs 32 which extend in a downwardly direction at right angles from a lower or under surface of the circular washer portion 28 and are preferably triangularly shaped as shown in FIG. 5. The tabs 32 are positioned between the insulated opening 24 of the coil 14 and the center post 16 as viewed in FIG. 2. By proper design of the different mating parts it is readily apparent that a frictional force fit of the tabs 32 between the post 16 and the coil 14 will be made which will assist the retention of the coil on to the post. If a plain washer 35, having no downwardly extending tabs as shown in FIGS. 7 and 8, is used then to insure a fixed relationship between the coil 14, the stator ends of the poles.

tion of the opening 24. The exposed end surface of center post 16 is flush with the upper exposed surface of the .Washer portion 28 when the adapter is in the secured position on the stator assembly.

Referring now to FIG. 6, an alternate form of the adapter'of this invention is illustrated with an irregular contoured upper portion 28 and depending tabs 32' which outline a central opening 30'. Like the preferred embodiment previously described, the irregular contour shown permits the steadying down of the flux paths with the recessed portions 36 aiding in the concentrating of the flux paths in a specific area.

In operation, the adapter 26 of this invention, when in the secured position on top of the AC. coil, with the Washer portion 28 between the coil 14 and the armature 18, as shown in FIG. 3, tends to steady down the flux paths with respect to the armature and to narrow down the effective gap between the poles so that a greater power is induced through the armature as it moves towards the As a result of this, there is a substantial reduction in the temperature rise in the A.C. coil. There will be little change in magnetic power and only a minute resetting of the armature 12 is required to maintain a constant torque output. Furthermore, it is well known that if the magnetic power is to be maintained at a constant level, additional input power must be supplied to offset reduction of the output due to the temperature rise in the AC. coil. The adapter 26 of this invention by substantially reducing the temperature rise in the AC. coil permits the maintaining of a constant magnetic power output without increasing the power input, thus reducing the overall wattage consumption.

The adapter 26 not only provides the novel function described above, but also serves as a securing means in holding the AC. coil in fixed relation with the center post 16. The overall contour and physical dimension of the adapter of this invention permits ready installation on existing stator structures and it is obvious that the length of the tabs and the contour of the central opening will be controlled by the stator assembly on which it is to be installed.

The embodiment of this invention as described, has been specific to the placing of the adapter on the center post of an E-shaped stator assembly. It is to be understood that the adapter of this invention reduces magnetic reluctance with a resultant increase of coil impedance and reduction of temperature rise whether the adapter is one which extends from the center post of the stator downwardly or whether it extends inwardly from an outer stator post.

Thus, it is seen that the invention has provided a novel adapter for mounting on stator structures which eifectively reduces the overall operational costs of electromagnetic devices, utilizing the reciprocating action of an armature, by substantially reducing the temperature rise of the A.C. coil of the stator assembly. It is realized that the actual details of the construction may be readily modified by one skilled in the art, and the inventor only intends to be limited to a reasonable interpretation of the appended claims covering the construction as illustrated and described.

What is claimed is:

1. A stator assembly in an electromagnetic device comprising a laminated stator having two poles defining a gap between them, an AC. coil positioned on one of the poles of the stator, an armature cooperating with said poles, a magnetic washer member having a central opening therethrough receiving said one pole member and having tab members extending in a direction from the washer member along said one pole, said tab members being mounted between the stator and the coil whereby the washer member will be positioned against a surface of the coil adjacent to the armature and with its periphery extending towards the other pole to narrow down the effective gap between the poles and efiectively concentrate the magnetic flux paths of the electromagnetic device to substantially reduce the power consumption while maintaining a constant value magnetic power output.

2. A stator assembly in an electromagnetic device for reducing the temperature rise of the stator assembly when in continuous operation and comprising a laminated E- shaped stator defining a gap between the center pole and each of the other poles, an electromagnetic coil on the center pole, an armature cooperating with said poles, a magnetic washer member having a central opening therethrough received on said center pole and having tab members integrally formed with and extending at right angles from said washer along said center pole and within said coil, said tabs being secured in contact with the center pole and with said washer member positioned against a surface of said coil adjacent to the armature to steady down the flux paths of the electromagnetic device and re- .duce the temperature rise of the stator assembly to effectively reduce the power consumption while maintaining the value of the magnetic power output.

3. The invention as set forth in claim 2 wherein the 'magnetic washer has an irregular external contour having a major dimension disposed in the direction of the other poles and extending a distance substantially less than the vdistance between said other poles of said E-shaped stator and said armature having'a dimension in the same direction greater than the distance between said other poles.

References Cited in the file of this patent UNITED STATES PATENTS 1,953,035 Wyss Mar. 27, 1934 2,452,678 Poole Nov. 2, 1948 2,511,174 Osborne June 13, 1950 2,616,733 Strange Nov. 4, 1952 2,768,337 Miller Oct. 23, 1956 

1. A STATOR ASSEMBLY IN AN ELECTROMAGNETIC DEVICE COMPRISING A LAMINATED STATOR HAVING TWO POLES DEFINING A GAP BETWEEN THEM, AN A.C. COIL POSITIONED ON ONE OF THE POLES OF THE STATOR, AN ARMATURE COOPERATING WITH SAID POLES, A MAGNETIC WASHER MEMBER HAVING A CENTRAL OPENING THERETHROUGH RECEIVING SAID ONE POLE MEMBER AND HAVING TAB MEMBERS EXTENDING IN A DIRECTION FROM THE WASHER MEMBER ALONG SAID ONE POLE, SAID TAB MEMBERS BEING MOUNTED BETWEEN THE STATOR AND THE COIL WHEREBY THE WASHER MEMBER WILL BE POSITIONED AGAINST A SURFACE OF THE COIL ADJACENT TO THE ARMATURE AND WITH ITS PERIPHERY EXTENDING TOWARDS THE OTHER POLE TO NARROW DOWN THE EFFECTIVE GAP BETWEEN THE POLES AND EFFECTIVELY CONCENTRATE THE MAGNETIC FLUX PATHS OF THE ELECTROMAGNETIC DEVICE TO SUBSTANTIALLY REDUCE THE POWER CONSUMPTION WHILE MAINTAINING A CONSTANT VALUE MAGNETIC POWER OUTPUT. 